1. Field of the Invention
The present invention relates to an oil well safety device that automatically shuts in or closes an oil well if the drill string is removed or responsive to removal of the drill string to a position above the safety device.
2. General Background of the Invention
In the exploration of oil, wells are drilled many thousands of feet into the earth. Tremendous pressures can exist in formations where oil is located. Drillers use heavy fluids such as drilling mud to control well pressures and prevent a catastrophic blow out wherein oil and gas escape from the well bore.
There are various control devices that hopefully close the well bore before a blow out can occur. Examples include blow out preventers, sub surface valves, sub surface safety valves and the like. Most such safety control devices require activation by personnel on a drilling structure. If these valve blow out preventers or valve structures cannot be actuated, blow out still occurs.